Classic BOAC FLT 716 - CTD - how to restore

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Classic BOAC FLT 716 - CTD - how to restore

Postby as099mw » 05 Apr 2007 19:33

This info may be useful when flying INS equipped aircrafts (like the HJG 707).

I'm now finishing the round-the-northern-hemisphere tour EGLL - OBBI - OMDB - VABB - VHHH - RJAA - PHNL - KSFO - KJFK - EGLL. I use several 707 versions (models by Histroic Jetliners Group) only. These aircrafts are equipped with the inertial navigation system (INS), which requires the aircraft to be steady during initialization (for about 20 to 30 minutes). It seems, that restoring the flight saved either manualy or using some autosave software is not possible. But it is possible, even after FS9 crash-to-desktop.

The CTD occured during the Classic BOAC flight 716 EGLL - OBBI after several hours of flying (caused by some AAS issue together with momentary lack of computer memory). The flight was restored succesfully even without any autosave.

What You need to know for the case of CTD and for the best recovery:

A. Aircraft position/heading/airspeed
There are two DME indicators on the HJG 707 main panel. If You maintain Your nav radios tuned, You always know Your position related to VOR/DMEs tuned. The INS indicates distance to the next waypoint, too.
Similarly, heading and airspeed is indicated by the instruments.


B. Fuel status
You surely know the initial fuel loaded. And You know the fuel burnt thanks to four flowmeters on the main panel.

What You need to do when crashed to desktop:

1. Avoid the FS9 automatic restart - important!
(uncheck the checkbox on the error message window) to avoid AAS confusion and data loss (especially the flight time).

2. Stop ActiveAirSource - important!
This allows to continue flight later (using the usual AAS save/continue feature).

During a CTD the whole computer and any software is unstable, therefore turning the AAS off ASAP is the best way to avoid unexpected and unwanted results.

3. Start FS9 and create a new flight.
Use the same aircraft and select any airport, preferably some close to the CTD position. The length of runways is not important - You will not use any. Load the fuel amount equal to the previous fuel status (B - see above). No flight plan is required at this moment.

4. Peroform alle the pre-flight business as usually.
In the case of the HJG 707 it means especially the INS initialization. When finished, start up Your engines. Any communication with GND/TWR is not needed.

5. Open the map window and set the aircraft parameters.
Altitude, heading and position will be the same as (A - see above). But not the airspeed. Remember, when the simulation starts, Your gear is down, therefore set the airspeed not too low to avoid stall but not too high to avoid gear damage.

6. Close the map window and You are ALMOST restored.
Your aircraft will probably be unstable a bit during the first seconds. Retract the landing gear immediately, set throttles and make Your flight stable. Now let the autopilot flies, heading-hold and altitude-hold modes on.

7. Start the AAS
If the AAS announces the unsaved flight, save it at first. After saving the flight I usually restart the AAS again. Now the AAS should indicate the saved flight and usual menu (pirep/save/continue flying). Select the saved flight, select continue flying and You are back on track.

8. Set up a new flight plan.
When flying IFR, You need a new flight plan. Open the flight planner and create a new F/P. The cruising altitude will be the same like in the original F/P (and the same You are flying at just now). Use the nearest airport as a departure waypoint (preferably some which is behind You and not too far to the left or right). Save the F/P and DO NOT allow the aircraft position to be set to the departure airport.

9. Request IFR clearance
Open the ATC window. You will see some choices like (Tune xxx center, Nearest airport list etc.). Tune the center and then select "Request IFR clearance. The ATC will give You a new heading to intercept the planned route. If Your new F/P is set up cleverly, no sharp turns will be ordered.

10. Set up INS waypoints and switch to INS guidance.
Do not forget to enter new waypoints to the INS. When finished, select FROM/TO waypoints and if everything is OK, turn the A/P INS mode on.

The above procedure can be used not only after CTD, but even to save a long haul INS guided flight. In this case You can write down all those values needed for the later restore. In any case, Your total flight time and total fuel used will be accurate as possible.

I did not test this procedure with the CIVA INS, which is very similar but slightly more complicated compared to the HJG 707 INS.

Cheers
Martin, AS099

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as099mw
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